Anderson-Lopez was raised in Croton-on-Hudson, New York, until 1986; the Myers Park neighborhood of Charlotte, North Carolina, from 1986 to 1990; and Waxhaw, North Carolina, from 1990 onward. Her parents, Erin and John, still live in Waxhaw. According to her father, Anderson-Lopez first fell in love with the theater at the age of four, when he took her to see a U.S. Bicentennial musical tribute staged in their then-hometown of Croton-on-Hudson. After her family moved to North Carolina, she attended and graduated from Charlotte Country Day School. She went on to Williams College in western Massachusetts, where she double-majored in drama and psychology and graduated in 1994. After a theater internship in Florida, Anderson-Lopez spent several years working temporary jobs while pursuing her dream of becoming a Broadway theatre performer in New York City. In 1999, she entered the BMI Lehman Engel Musical Theatre Workshop and found her true calling as a lyricist, and also met her future husband Robert Lopez. In October 2003, Anderson married Lopez, who would go on to become an EGOT-winning songwriter, composer and lyricist, including three Tony Awards for Avenue Q and The Book of Mormon. They have two daughters; Katie and Annie, who both had voice parts in Frozen. Anderson-Lopez's sister, Kate Anderson, co-wrote the songs for Olaf's Frozen Adventure.
Anderson-Lopez's first collaborations with her husband involved writing several songs together for children's televisions shows, such as Wonder Pets on Nick Jr and Bear in the Big Blue House on the Disney Channel. Anderson-Lopez, along with her husband Robert Lopez and Henry Jackman, wrote and produced music for the 2011 Disney film Winnie the Pooh, for which they were nominated for an Annie Award for Best Music in a Feature Production. She also provided the voice of Kanga in the film. Her work with her husband writing songs for the 2013 Disney film Frozen, including "Let It Go", won her an Academy Award for Best Original Song at the 86th Academy Awards and two Grammy Awards at the 57th Annual Grammy Awards. Anderson-Lopez and her husband also wrote the music for the sequel, Frozen II. Kristen Anderson-Lopez and Robert Lopez again collaborated in writing songs and lyrics for the 2017 Pixar film Coco, for which she won for an Annie Award for Music in a Feature Production. She also won an Academy Award for Best Original Song for the song "Remember Me" at the 90th Academy Awards. Kristen Anderson-Lopez sings Elsa’s role in “I Seek the Truth”, an outtake song of the Frozen II soundtrack, along with Patti Murin singing Anna’s part, who originated the role of Anna in the Broadway production of Frozen.
